A fully distributed method for dynamic spectrum sharing in femtocells

The traffic in cellular networks has been growing at an accelerated rate. In order to meet the rising demand for large data volumes, shrinking the cell size may be the only viable option. In fact, locally deployed small cells, namely picocells and femtocells, will certainly play a major role in meeting the IMT-Advanced requirements for the next generation of cellular networks. Notwithstanding, several aspects of femtocell deployment are very challenging, especially in closed subscriber group femtocells: massive deployment, user definition of access point location and high density. When such characteristics are combined the traditional network planning and optimization of cellular networks fails to be cost effective. Therefore, a greater deal of automation is needed in femtocells. In particular, this paper proposes a novel method for autonomous selection of spectrum/ channels in femtocells. This method effectively mitigates cotier interference with no signaling at all across different femtocells. Still, the method has a remarkable simple implementation. The efficiency of the proposed method was evaluated by system level simulations. The results show large throughput gains for the cells with unfavorable geometry, up to nearly 300% when compared to the unmanaged situation (reuse 1).